1. Field of the Invention
This invention relates to an intraocular lens and more particularly to an intraocular lens to be implanted in the anterior chamber of an eye.
2. Description of the Related Art
Intraocular lenses have been used for years for implantation after surgery such as extracapsular cataract extraction, ultrasonic emulsifying aspiration, and so on. Most typical intraocular lenses are those to be implanted within lens capsules in posterior chambers (hereinafter called posterior chamber lenses). However, there are some particular conditions of surgery which make it impossible to fix the intraocular lens in the posterior chamber. In such cases, the intraocular lens, after being placed in the posterior chamber, must be sutured to the ciliary sulcus; otherwise, it is placed in the anterior chamber.
Suturing an intraocular lens to a ciliary sulcus is a very difficult technique which requires a high skill and expensive equipment for removal of a front part of the vitreous body. Moreover, since this method makes a large surgical invasion, it may cause any trouble in the oculus, or some other troubles which are currently unknown but may possibly be realized after many years.
In contrast, implantation of an intraocular lens in the anterior chamber requires neither a high skill nor expensive equipment. However, intraocular lens so far available for placement in the anterior chamber (hereinafter called anterior chamber lenses) were designed to be fixed by engagement with the anterior chamber angle. Therefore, these anterior chamber lenses were liable to damage a wide area of the anterior chamber angle. Moreover, internal support of conventional anterior chamber lenses was unreliable and could not prevent their rotating or other motional displacement. These could be large factors in inflammation or other like troubles of the corneal endothelium which might further invite damage to the iris after surgery.